Welcome Astro 7 Students
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Critique the following statements from the perspective of the scientific method, explaining what, if anything, is wrong with each one or what you would like to know in order to clarify each one. a) "Nine out of ten scientists believe in the big bang model for the creation of the universe, so I believe it too. b) "Nine out of ten scientific reports published in an international medical journal find that a certain food additive causes cancer in mammals and advise against using it, so for the time being, I'm going to try avoid using it, although I recognize that future tests may give different answers." c) "My favorite talk show host says that a certain food additive causes cancer, so I'm going to stop using it." d) "team, I want you to go out there and give 110 percent." e) "The cake probably weighs 2.3461 kilograms." f) "Wind is caused by trees waving their branches." g) "Lung cancer is caused by smoking." h) :There is no chance that Los Angeles will suffer a major destructive earthquake within the next 10 years.
Answer the following questions, assuming that typical interplanetary material moves at about 15 km/s relative to the Earth-Moon system. a) If a kilometer-scale asteroid were discovered on a collision course with Earth when it was 15 million km away, how much warning time would we have? b) What would be the potential dangers of such an asteroid's collisions with Earth? c) If a much smaller asteroid were similarly discovered at the distance of the Moon (384,000 km), how much warning time would we have? d) Roughly how long would the objects take ht pass through the 100 km thickness of the atmosphere?
If 100,000 meteorites capable of killing someone strikes Earth's surface every year, what is the probability that anyone has been killed in recorded history? This problem is simple, but you need to make some assumptions to solve it. Assume that the meteorites hit random positions on the Earth's surface. You will need to estimate an average population over the time period you consider. You will also need to estimate the cross sectional area as seen from above of a person. Hint: What is the fraction of Earth's surface that is "covered" by people? Why is it more likely that someone would have been hit by a meteorite in this century than at any other time in hisotry?
This page was last modified on April 5, 2000